Researchers affiliated with several institutions in the United States have determined that the increase in the number of hurricanes forming in the Atlantic over the past several years is not related to global warming. They suggest instead, in their paper published in the journal Nature Communications, that it is simply reflective of natural variable weather patterns.
Over the past several decades, scientists studying satellite data have found that the number of hurricanes forming in the Atlantic Ocean has been increasing. Many in the field have suggested that this is due to the impact of global warming. A warming ocean, they note would naturally lead to more active atmospheric activity. The problem with such thinking, the researchers from this new effort note, is that satellite data only goes back to 1972. Prior to that date, data on hurricane frequency tended to come from eyewitness accounts, which left out many hurricanes that never touched land.
In this new study, the researchers went back to the old record books to learn more about the frequency of hurricanes prior to satellites.
The old-time data stretched as far back as 1851 and came courtesy of records kept by workers at the National Oceanic and Atmospheric Administration. The workers had collected the data from eyewitnesses across the eastern seaboard, along the Gulf of Mexico, islands in the Atlantic and fishermen venturing out to sea. The researchers then calculated the ratios of hurricanes that never came ashore in modern times to those that did, and worked backwards using modern data along with math techniques to estimate the number of hurricanes going back to 1860 that were never recorded. They then plotted those numbers on a timeline.
Researchers found no evidence on the timeline of larger than normal numbers of hurricanes forming over the past few decades—instead, it showed that the numbers were on par with prior spikes in the late 1940s and early 1880s. They also found no evidence indicating that modern hurricanes are any more powerful than those in the past.
More information: Gabriel A. Vecchi et al, Changes in Atlantic major hurricane frequency since the late-19th century, Nature Communications (2021). DOI: 10.1038/s41467-021-24268-5